Ocena zróżnicowania ekstremalnie wysokich przepływów wybranych rzek polskich

The paper presents the results of estimation and comparison of risk of extreme floods on rivers of various hydrological regimes. The hypothesis that extreme events occur with the same frequency in all rivers has been refuted. The borderline between extreme and common floods on 30 rivers from various geographical regions of Poland was defined on the basis of the standardized flow-duration curve for 1971-2006. The analyses resulted in grouping the curves into 6 groups. Four measures of flood magnitude have been proposed. The time distribution of extreme events during the last decades was estimated for the most dynamic rivers.